利塞膦酸钠对非骨水泥型全髓关节置换术后早期股骨假体周围骨密度的影响

目的 探讨利塞膦酸钠对非骨水泥型全髋关节置换术后早期股骨假体周围骨密度的影响及治疗作用,以其为临床提供防止假体周围骨丢失和松动的预防措施和处理方法.方法 2011年3月～2012年5月于本院行非骨水泥型人工全髋关节置换术中符合纳入标准的患者共26例随机分成利塞膦酸钠组与对照组;试验组术后每日口服利塞膦酸钠5 mg+钙剂600 mg,而对照组仅服用钙剂600 mg;分别于术后1周、3、6个月测定股骨近端各感兴趣区(ROI)的骨密度.结果 获得完整病例24例,术后3、6个月各区骨密度均呈持续下降趋势,和对照组相比,术后3个月利塞膦酸钠组股骨假体(ROI1、ROI7)的差异有统计学意义(P＜0.01),其余各测量区骨密度2组相比差异无统计学意义(P＞0.05).与对照组相比,术后6个月利塞膦酸钠组股骨假体(ROI1、ROI7)的差异有统计学意义(P＜0.01),其余各测量区骨密度2组相比差异无统计学意义(P＞0.05).结论 利塞膦酸钠能够有效的减少非骨水泥型全髋关节置换术后假体周围的骨丢失,从而减缓假体松动,延长假体使用寿命.     

阿仑膦酸钠对骨质疏松性大鼠钛合金假体骨整合影响的实验研究

[目的]观察阿仑磷酸钠对骨质疏松大鼠假体骨整合的影响。[方法]SD雌性大鼠39只,双侧胫骨结节处垂直骨面置入定制钛合金假体,随机分为正常组、对照组、治疗组(每组13只),正常组不做任何处理;对照组和治疗组8周后行双侧切除卵巢建立骨质疏松模型。骨质疏松模型建成后,对照组术后每周空腹生理盐水灌胃;治疗组术后每周空腹阿仑膦酸钠灌胃,剂量1 mg/(kg/周),持续8周。灌胃结束后处死取材,进行组织学观察及组织形态计量学测定。[结果]组织学观察发现,正常组假体周围纤维界膜薄且稀少,新生骨与假体界面为直接接触,大部位新生骨与假体界面完全整合。对照组假体周围由新生骨、类骨质和纤维界膜构成。纤维界膜较厚,与新生骨或类骨质间界限清晰。治疗组假体周围纤维界膜薄且稀少,新生骨与假体界面多为直接接触,有些部位新生骨与假体界面完全整合。组织形态计量学测定发现,治疗组假体周围界膜的厚度和面积均明显大于对照组,差异有统计学意义(P<0.05)。[结论]阿仑膦酸钠经胃肠给药对骨质疏松大鼠假体骨整合有一定的促进作用。     

阿仑膦酸钠对人工关节假体周围骨长入的影响

目的观察阿仑膦酸钠对人工关节假体周围骨长入的影响。方法SD雄性大鼠16只,双侧胫骨上端经膝关节植入定制钛合金假体,随机分成对照组和实验组,对照组术后每日空腹生理盐水灌胃;实验组术后每日空腹阿仑膦酸钠灌胃,剂量0.1 mg/(kg.d),持续6周。术后12周处死取材,进行组织学观察及组织形态计量学测定。结果组织学观察发现,对照组假体周围由新生骨、类骨质和纤维界膜构成。纤维界膜较厚,与新生骨或类骨质间界限清晰。实验组假体周围纤维界膜薄且稀少,新生骨与假体界面多为直接接触,有些部位新生骨与假体界面完全整合。组织形态计量学测定发现,对照组假体周围界膜的厚度和面积均明显大于实验组,差异有显著性(P<0.05)。结论阿仑膦酸钠经胃肠给药可能对钛合金人工关节假体周围骨长入有一定的促进作用。     

静脉伊班膦酸钠冲击治疗类固醇性骨质疏松症的临床对照研究

目的评价伊班膦酸钠治疗类固醇性骨质疏松症的有效性和安全性。方法采用随机、对照研究。153例类固醇性骨质疏松症患者,随机分为埘照组(C组,49例)、伊班膦酸钠治疗组(Ⅰ组,52例)和阿法骨化醇治疗组(R组,52例)。3组患者均每天补充碳酸钙600mg/d。Ⅰ组:应用伊班膦酸钠注射液静脉点滴,3个月1次,每次2mg。R组:罗钙全0.25μg/d,口服。疗程6个月。观察伊班膦酸钠治疗后患者腰椎骨密度、股骨颈骨密度、全段甲状旁腺激素(iPTH)、血钙、血磷、血清碱性磷酸酶(AKP)等骨代谢指标的变化及不良反应发生情况。结果(1)治疗6个月后,Ⅰ组、R组腰椎及股骨颈骨密度均较C组明显上升[腰椎骨密度(g/cm2):Ⅰ组比C组,1.28±0.04比0.82±0.04,P<0.01;R组比C组,1.14±0.03比0.82±0.04,P<0.05;股骨颈骨密度(g/cm2):Ⅰ组比C组、1.29±0.04比0.90±0.04,P<0.05;R组比C组,1.21±0.06比0.90±0.04,P<0.05]。(2)治疗6个月后,Ⅰ组和R组血iPTH水平均较C组下降[Ⅰ组比C组,39.02±1.28比90.67±10.02(pg/ml),P<0.01;R组比C组,52.43±1.42比90.67±10.02(pg/ml),P<0.05]。(3)伊班膦酸钠治疗后,患者无严重不良反应发生。结论伊班膦酸钠是一种治疗类固醇性骨质疏松症的有效而安全的药物,其升高骨密度的作用比阿法骨化醇明显,且静脉应用患者依从     

载阿仑膦酸钠骨水泥抑制钛磨屑诱导的假体周围骨溶解

目的 比较载阿仑膦酸钠丙烯酸骨水泥与皮下注射阿仑膦酸钠抑制钛磨眉诱导的骨溶解的效果.方法 48只成年雄性新西兰兔随机均分为无钛磨屑且无阿仑膦酸钠组(A组),有钛磨屑注射且无阿仑膦酸钠组(B组),钛磨屑分别注射0.1%、0.5%、1.0%载阿仑膦酸钠丙烯酸骨水泥组(C、I)、E组),钛磨屑注射且皮下手射阿仑膦酸钠组(F组),每组8只.将载阿仑膦酸钠骨水泥植入兔股骨远端.制备磨屑诱导骨溶解动物模型.术后8周对股骨行组织形态学分析、骨密度(bone mineral density,BMD)测定及界面力学测试结果 B组假体周围可见明显的骨溶解,而C、D、E、F组骨溶解明显少于B组.B组假体周围BMD和骨-骨水泥界面抗剪强度分别较A组下降17%和56%;D组假体周围BMD和界面抗剪强度较B组分别增加29%和62%;E组假体周围BMD和界画抗剪强度较B组分别增加37%和29%;F组假体周围BMD和界面抗剪强度较B组分别增加51%和69%;C组、D组、E组分别与F组比较,假体周围BMD和界面抗剪强度的差异均无统计学意义.结论 载阿仑瞵酸钠丙烯酸骨水泥与皮下注射阿仑瞵酸钠均可在一定程度上抑制磨屑诱导的骨吸收,增强界画抗剪强度.     

阿仑膦酸钠和鲑鱼降钙素对骨质疏松骨床中假体骨整合影响的对比研究

目的探讨阿仑膦酸钠(ALO)和鲑鱼降钙素(CT)两种药物促进假体骨整合作用效果的差异,为临床药物的选择应用提供参考。方法将40只雌性SD大鼠随机分为四组(A,B,C,D组),每组10只。切除B、C、D组大鼠卵巢建立骨质疏松(OP)模型(骨密度降幅20%),A组行假手术做为对照。随后在大鼠的胫骨平台植入羟基磷灰石假体,术后C、D组分别给予皮下注射CT(5IU/kg/d)和口服ALO(7mg/kg/w)各12周,A、B组做药物干预的对照组。所有大鼠在处死前,行体内荧光染色。处死后取带假体的胫骨制备成薄片,运用骨组织计量学检测手段,观察假体周围的骨量和测量假体的骨结合率。结果(1)ALO和CT两者均能促进假体周围成骨,增加骨量,显著提高骨-假体界面骨结合率至63.7%和45.7%,较OVX组骨整合比率分别提高近1～2倍,但阿仑膦酸钠促进假体周围成骨与促进骨整合较鲑鱼降钙素作用更为显著(P0.05),骨结合率增加18%;(2)阿仑膦酸钠和鲑鱼降钙素组大鼠腰椎BMD均提高,分别从(0.081±0.009)g/cm2和(0.078±0.009)g/cm2提至(0.116±0.008)g/cm2和(0.109±0.010)g/cm2。而且,阿仑膦酸钠的效果较降钙素更为明显。结论骨质疏松条件下,全身给予阿仑膦酸钠和鲑鱼降钙素均可增强假体周围成骨及骨量,有效促进假体的骨整合,但与鲑鱼降钙素相比,阿仑膦酸钠作用更为明显。     

药物抑制磨损颗粒所致骨溶解的动物实验研究

[目的]探讨药物预防人工关节磨损颗粒致假体周围骨溶解及无菌性松动的可能性.[方法]成年新西兰兔双侧股骨髁和胫骨平台横向钻4 mm×8 mm孔洞,不同部位分别植入CoCr合金(平均5.38 μm)、Ti合金(平均3.21 μm)及超高分子聚乙烯(UHMWPE)颗粒(12～200 μm)各1 mg,植入组配相同者为1组,共4组,每组3只.随机确定给药组,分别经口饲给予非选择性COX阻断剂-消炎痛0.5 mg/kg体重、钙通道阻滞剂-尼群地平0.1 mg/kg体重以及破骨细胞抑制剂-阿仑膦酸钠0.1 mg/kg体重,生理盐水为空白对照,2次/d,双盲实验.术后12周处死取材,脱钙切片,组织学观察、计算机图像分析测量并计算BA/TTA比值.[结果]CoCr合金和Ti合金颗粒各组切片中少见颗粒,正常松质骨表现.空白对照组双折光性UHMWPE颗粒周围大量炎性纤维组织细胞反应;消炎痛与尼群地平组相似,组织细胞反应相对空白对照组稍弱,偶见增生纤维组织中骨样组织存在.阿仑膦酸钠组UHMWPE颗粒包埋于骨组织中,组织细胞反应及纤维组织增生少见,间有髓样组织.UHMWPE颗粒阿仑膦酸钠组BA/TTA比值明显高于空白对照组(P<0.01),消炎痛和尼群地平组之间及其与空白对照组之间则无显著性差异(P>0.05).[结论]药物抑制或预防磨损颗粒性骨溶解及假体无菌性松动具有一定的可行性,其中阿仑膦酸钠的作用较为肯定,值得进一步作体内外相关研究及临床验证.     

阿伦膦酸钠防治人工关节松动的实验研究

目的：评价二膦酸盐阿伦膦酸钠在防治人工关节松动中的作用。方法：36只SD大鼠右膝置入自制人工关节假体,建立人工关节松动的动物模型,分成3组：阴性对照组,阳性对照组和实验组。阴性对照组关节腔内注射磷酸缓冲液与鼠血清混合液,阳性对照组关节腔内注射10^10/ml关节磨屑（超高分子聚乙烯颗粒）,实验组关节腔内注射10^10/ml关节磨屑同时用阿伦膦酸钠灌胃（每日1mg/kg）。术后12周,处死各组动物行组织切片对比观察假体周围骨溶解情况。体外分离培养人外周血单个核细胞并分成5组,A组为单核细胞组,B组为单核细胞和关节磨屑混合培养组,C组为单核细胞和关节磨屑混合培养加入10^-4mol/L阿伦膦酸钠,D组单核细胞和关节磨屑混合培养加入10^-5mol/L阿伦膦酸钠,E组为单核细胞和关节磨屑混合培养加入10^-6mol/L阿伦膦酸钠,检测各组单个核细胞分泌溶骨因子的情况。结果：关节磨屑可引起假体周围骨溶解,刺激单个核细胞分泌溶骨因子,阿伦膦酸钠可阻止这种作用。结论：阿伦膦酸钠可有效防止关节磨屑诱导的人工关节松动,有望用于临床。     

非骨水泥型全髋关节置换术治疗酒精性股骨头坏死

[目的]研究非骨水泥型全髋关节置换术治疗酒精性股骨头坏死的中期疗效.[方法]1997年3月～2002年6月,采用非骨水泥型全髋关节置换术治疗酒精性股骨头坏死41例(47髋),进行至少5年的随访、中期临床评估和影像学评估.临床评估以Harris评分为标准.影像学根据骨盆正位和髋关节侧位X线片,观察髋臼、股骨假体的位置以及周围骨质的改变.假体的生存率采用Kaplan-Meier分析,分别以股骨、髋臼假体的无菌性松动和任何原因所致的翻修为终点.[结果]得到至少5年随访的41例(47髋),术前Harris评分为42.4±6.4(24～49)分,最后1次随访评分为91.8±4.4(74～100)分.至最后1次随访时无1例翻修或表现为影像学无菌性松动,2髋出现骨盆局灶性骨溶解,6髋出现股骨局灶性骨溶解.Kaplan-Meier分析假体的生存率1.0(95%可信区间,0.98～1.0).[结论]非骨水泥型全髋关节置换术可为晚期酒精性股骨头坏死患者提供良好的中期临床效果.由于假体磨损、假体周围骨溶解等潜在因素,长期效果需要进一步随访.     

强直性脊柱炎股骨近段形态学改变对全髋关节置换术假体选择的意义

目的分析强直性脊柱炎股骨近段的形态学改变,及其改变对全髋关节置换术假体选择的意义。方法1999年1月~2004年6月,将13例(16髋)强直性脊柱炎患者设为选择组,患者均已出现关节强直,需行全髋关节置换术。另16例(19髋)为对照组,为非强直性脊柱炎患者而拟行全髋关节置换术。两组患者均摄髋关节正侧位X线片,测量Singh指数、髓腔张开指数、皮质形态指数及皮质骨指数,并进行统计学分析。结果选择组Singh指数、髓腔张开指数及皮质形态指数分别为3.81±0.54、2.63±0.41及2.02±0.38,对照组分别为4.63±0.62、3.03±0.27及2.76±0.28,两组比较差异均有统计学意义(P<0.05)。选择组皮质骨指数为1.69±0.69,对照组为2.12±0.24,两组比较差异无统计学意义(P>0.05)。选择组患者髓腔呈烟囱型10例13髋,普通型3例3髋;对照组烟囱型3例3髋,普通型13例16髋。结论强直性脊柱炎的全髋关节置换术应采用骨水泥型人工关节假体,并根据患者髓腔形态使用定制型骨水泥假体,以达到更好的近段固定效果。对于有严重骨质疏松者应按关节翻修术处理。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). Methods: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre-and intra-operative arterial blood gases and O₂ flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg^?1· h^?1 vs. 6.6 ± 4.8 μg · kg^?1· h^?1), a lower O₂ supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd?/procedure). Intraoperative PaCO₂ was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.